Most of the current generation of automated or semi-automated sawmills utilize a set of spaced, parallel double saw blades which slice through the log simultaneously, either to remove the outer portions of the log or to slice the log into boards. Various means have been developed for feeding the logs through the saw blade area, for example gripping members or dogs which hold the log by each end. These dogs may also be used to rotate the log so as to locate the uncut sides in position to be cut by the saw blades. One example of this type of sawmill is found in U.S. Pat. No. 3,747,455, to Hartzell et al.
One disadvantage of this type of arrangement is that the procedure is relatively slow and may not be able to accept logs of a certain length or girth. Thus, some logs may need to be cut in half before processing or even sliced lengthwise or quartered before they can be processed. Obviously, the faster the operation can be accomplished, the more cost effective it becomes; however, the operation must also be precise enough to avoid removing excess usable lumber from the logs being cut.
Our prior patent, U.S. Pat. No. 4,287,798 for a Sawmill Work Feeding and Product Handling Apparatus used opposed, parallel supporting rollers to orient the log to a position where dogs can engage the log on opposite ends. The device provides greater flexibility in handling the log, moving the log forwardly and then rearwardly through the saw blades, again cutting the logs one at a time.